Tosaf develops new antistatic masterbatch optimised for PP packaging

Tosaf has developed a new antistatic masterbatch optimised for polypropylene packaging that it says remains highly effective even at very low atmospheric humidity.

New ST7505HP has low rates of addition of just one to five percent for extrusion and three to five percent for injection moulding, which bring about a significant reduction of the high electrical surface resistance typical for products made of PP. As a result, the company says electrical charges can quickly be reduced from moulded parts, rigid packaging or films, even in regions with a dry climate.

"We had already developed products for polyethylene which similarly retained their effect even at very low humidity. ST7505HP means we can now meet this requirement for the entire range of polyolefins and their applications as packaging materials, for example for foodstuffs, personal care, electrical and electronic products,” explained Irina Shtein Rozenman from Tosaf's additives R&D division explains.

The new masterbatch has no effect on the colour and transparency of a material and meets FDA and EU requirements for food contact. Tosaf says in laboratory testing, ST7505HP has demonstrated an “excellent antistatic effect”, which is retained over the long term – even at just 12 percent RH – whereas conventional additives of this kind, such as hydrophilic surfactants, require a significantly higher atmospheric humidity in order to be effective. The new antistatic additive ensures, therefore, that electrical charges, which may attract dust or could damage and even destroy electronic devices, do not build up after extended dry storage or after frictional contact with other surfaces.

Tosaf says ST7505HP is particularly suitable for PP packaging used in the electronics industry, as it doesn’t show a corrosive effect on the polycarbonate (PC) that is frequently used in this sector and therefore doesn’t cause stress cracking of the PC boards. In the film processing industry, ST7505HP can enable higher production speeds because film layers can be more easily separated from one another.